Photoelectric conversion device

Abstract

A photoelectric conversion device for detecting the spot size of incident light, includes a photoelectric conversion element having a photoelectric conversion substrate with two main surfaces, and first and second sensitivity section sections; and scanners that relatively scan incident light on the main surfaces of the photoelectric conversion element. When a sensitivity region on a main surface of the first sensitivity section is defined as a first sensitivity region and sensitivity regions that appear on a main surface of the second sensitivity sections are defined as second sensitivity regions, the first sensitivity region receives at least part of the light incident on the main surface during scanning, and has a pattern in which, in accordance with enlargement of an irradiation region irradiated with incident light on the main surface, the proportion of the first sensitivity region with respect to the second sensitivity regions in the irradiation region is decreased.

What is claimed is: 
     
       1. A photoelectric conversion device comprising:
 a photoelectric conversion element including a photoelectric conversion substrate having first and second principal surfaces, the photoelectric conversion substrate including a first sensitive part and a second sensitive part; and 
 a scanner configured to relatively scan the first principal surface of the photoelectric conversion element with incident light, 
 wherein 
 the first sensitive part defines a first sensitive region on the first principal surface and the second sensitive part defines a second sensitive region on the first principal surface, 
 the first sensitive region is configured to receive, during scanning by the scanner, at least a portion of the incident light incident on the first principal surface in an irradiation region, 
 the first sensitive region forms a pattern such that a ratio of an area of the first sensitive region in the irradiation region to an area of the second sensitive region in the irradiation region decreases as a size of the irradiation region increases, 
 the first sensitive part and the second sensitive part of the photoelectric conversion element have different photoelectric conversion characteristics, 
 the photoelectric conversion substrate of the photoelectric conversion element contains a single-crystal silicon material, 
 the photoelectric conversion element including
 a first conductivity type semiconductor layer formed at one of the first and second principal surfaces of the photoelectric conversion substrate, and 
 a second conductivity type semiconductor layer formed at an other of the first and second principal surfaces of the photoelectric conversion substrate, 
 
 in the photoelectric conversion element, the second sensitive part has a photoelectric conversion characteristic lower than that of the first sensitive part, and 
 the photoelectric conversion element further includes passivation layers formed on the first and second principal surfaces in the first sensitive part, such that the passivation layers are absent from at least one of the first and second principal surfaces in the second sensitive part. 
 
     
     
       2. The photoelectric conversion device according to  claim 1 , wherein
 the first sensitive region of the photoelectric conversion element forms at least one strip-like pattern on the first principal surface, and 
 the scanner is configured to scan in a direction intersecting a longitudinal direction of the strip-like pattern. 
 
     
     
       3. The photoelectric conversion device according to  claim 1 , wherein
 in the photoelectric conversion element, the first sensitive part further defines the first sensitive region on the second principal surface and the second sensitive part further defines the second sensitive region on the second principal surface, and 
 the photoelectric conversion element further comprises
 a first one of the passivation layers, the first conductivity type semiconductor layer and a first transparent electrode layer successively formed at the first principal surface in the first sensitive region and the second sensitive region, and 
 a second one of the passivation layers, the second conductivity type semiconductor layer and a second transparent electrode layer are successively formed at the second principal surface in the first sensitive region, such that the second one of the passivation layers, the second conductivity type semiconductor layer and the second transparent electrode layer are absent from the second sensitive rcgionpart on the second principal surface. 
 
 
     
     
       4. The photoelectric conversion device according to  claim 1 , wherein
 in the photoelectric conversion element, the first sensitive part further defines the first sensitive region on the second principal surface and the second sensitive part further defines the second sensitive region on the second principal surface, and 
 the photoelectric conversion element further comprises
 a second one of the passivation layers, the second conductivity type semiconductor layer and a second transparent electrode layer successively formed at the second principal surface in the first sensitive region and the second sensitive region, and 
 a first one of the passivation layers, the first conductivity type semiconductor layer and a first transparent electrode layer successively formed at the first principal surface in the first sensitive region, such that the first one of the passivation layers, the first conductivity type semiconductor layer and the first transparent electrode layer are absent from the second sensitive part on the first principal surface. 
 
 
     
     
       5. The photoelectric conversion device according to  claim 1 , further comprising
 an other photoelectric conversion element arranged on an upstream side of the incident light, and 
 wherein the photoelectric conversion element is arranged on a downstream side of the incident light. 
 
     
     
       6. The photoelectric conversion device according to  claim 5 , further comprising
 a calculator configured to calculate a spot size of the incident light on the photoelectric conversion element based on an output current of the other photoelectric conversion element and a maximum output current of the photoelectric conversion element during scanning by the scanner. 
 
     
     
       7. The photoelectric conversion device according to  claim 6 , wherein
 the first sensitive region of the photoelectric conversion element forms at least one strip-like pattern on the first principal surface, and 
 the photoelectric conversion element includes a plurality of electrodes that output currents, the plurality of electrodes being separately arranged on two longitudinal sides of the strip-like pattern of the first sensitive region of the photoelectric conversion element. 
 
     
     
       8. The photoelectric conversion device according to  claim 1 , wherein the first sensitive part and the second sensitive part of the photoelectric conversion element are separated from each other. 
     
     
       9. The photoelectric conversion device according to  claim 8 , wherein
 the first sensitive part further defines the first sensitive region on the second principal surface and the second sensitive part further defines the second sensitive region on the second principal surface, and 
 at at least one of the first and second principal surfaces of the photoelectric conversion substrate of the photoelectric conversion element, the first sensitive region and the second sensitive region are separated from each other. 
 
     
     
       10. The photoelectric conversion device according to  claim 8 , further comprising
 an optical lens arranged on an upstream side of the incident light, 
 wherein the photoelectric conversion element is arranged on a downstream side of the incident light. 
 
     
     
       11. The photoelectric conversion device according to  claim 10 , further comprising
 a calculator configured to calculate a spot size of the incident light on the photoelectric conversion element based on an output current of the first sensitive part and a maximum output current of the second sensitive part in the photoelectric conversion element during scanning by the scanner. 
 
     
     
       12. The photoelectric conversion device according to  claim 11 , wherein
 the first sensitive region of the photoelectric conversion element forms at least one strip-like pattern on the first principal surface, and 
 the photoelectric conversion element includes
 a plurality of first electrodes that output a first current from the first sensitive part, and 
 
 a plurality of second electrodes that output a second current from the second sensitive part, and 
 the plurality of first electrodes and the plurality of second electrodes are separately arranged on two longitudinal sides of the strip-like pattern of the first sensitive region of the photoelectric conversion element. 
 
     
     
       13. A photoelectric conversion device comprising:
 a photoelectric conversion element including a photoelectric conversion substrate having first and second principal surfaces, the photoelectric conversion substrate including a first sensitive part and a second sensitive part; 
 a scanner configured to relatively scan the first principal surface of the photoelectric conversion element with incident light; and 
 an optical lens arranged on an upstream side of the incident light, 
 wherein 
 the first sensitive part defines a first sensitive region on the first principal surface and the second sensitive part defines a second sensitive region on the first principal surface, 
 the first sensitive region is configured to receive, during scanning by the scanner, at least a portion of the incident light incident on the first principal surface in an irradiation region, 
 the first sensitive region forms a pattern such that a ratio of an area of the first sensitive region in the irradiation region to an area of the second sensitive region in the irradiation region decreases as a size of the irradiation region increases, 
 the first sensitive part and the second sensitive part of the photoelectric conversion element are separated from each other, and 
 the photoelectric conversion element is arranged on a downstream side of the incident light.